^ English is the official language of at least 28 states; some sources give higher figures, based on differing definitions of "official".[9] English and Hawaiian are both official languages in the state of Hawaii.

^ The population estimate is of people whose usual residence is within the 50 states and the District of Columbia, regardless of nationality. It does not include those living in the territories (over 4 million people, mostly in Puerto Rico).

The president is in charge of many departments that control much of the day-to-day business of government. For example, Department of Commerce makes rules about trade and business. The president chooses the heads of these departments, and also nominates federal judges. However, the Senate, part of the legislative branch, must agree with all of the people the president chooses. The president may serve two 4-year terms.

One house is the House of Representatives. The Representatives are each elected by voters from a set area within a state. The number of Representatives a state has is based on how many people live there. Every 10 years, the United States Census Bureau counts the population of the United States. States gain or lose Representatives based on the count. Representatives serve two-year terms. The total number of representatives today is 435. The leader of the House of Representatives is the Speaker of the House, who would become president if the president and vice president were unable to serve.

The other house is the Senate. In the Senate, each state is represented equally, by two senators. Because there are 50 states, there are 100 senators. Before the President makes treaties or appoints officials, the Senate must approve them. Senators serve six-year terms. The Vice President of the United States serves as president of the Senate. In practice, the vice president is usually absent from the Senate, and a senator is selected to serve as president pro tempore, or temporary president, of the Senate.

Representatives and senators propose laws, called "bills", in their respective houses. A bill may be voted upon by the entire house right away or may first go to a small group of members of that house, known as a committee, which may recommend a bill for a vote by the whole house. If one house votes to pass a bill, the bill then gets sent to the other house; if both houses vote for it, it is then sent to the president, who may sign the bill into law or veto it. If the president vetoes the bill, it is sent back to Congress. If Congress votes again and passes the bill with at least a two-thirds majority, the bill becomes law and cannot be vetoed by the president.

Under the American system of federalism, Congress may not make laws that directly control the states; instead, Congress may use the promise of federal funds, or special circumstances such as national emergencies, to encourage the states to follow federal law. This system is both complex and unique.

The Judicial Branch is the part of government that interprets what the law means. The Judicial Branch is made up of the Supreme Court and many lower courts. If the Supreme Court decides that a law is not allowed by the Constitution, the law is said to be "struck down" and is no longer a valid law. The Supreme Court is made up of nine judges, called justices, who are nominated by the President and confirmed by the Senate. One of these justices, called the chief justice, heads the court. A Supreme Court justice serves until he or she dies or resigns (quits in the middle of his or her term). When that happens, the president nominates someone new to replace the justice who left. If the Senate agrees with that choice, the person becomes a justice. If the Senate does not agree with the president's choice, then the president must nominate someone else.

The United States of America consists of 50 states, 5 territories and 1 district (Washington D.C.). States can make laws about things inside the state, but federal law is usually about things dealing with more than one state or dealing with other countries. In some areas, if the federal government makes laws that say different things from the state laws, people must follow the federal law because the state law is not a law any more. Each state has a constitution of its own, different from the federal (national) Constitution. Each of these is like the federal Constitution because they say how each state's government is set up, but some also talk about specific laws.

The federal and most state governments are dominated by two political parties: the Republicans and the Democrats. There are also many smaller parties; the largest of these are the Libertarian Party and the Green Party. People give money to political campaigns that they like, and try to persuade politicians to help them. This is called lobbying. All Americans are allowed to lobby the government, but some have and spend more money than others, or in other ways do more in politics. Some people think this is a problem, and want rules to be made to change it.

Since 2009, the president is a Democrat, so Democrats have slightly more power in the federal government. However, there are still many powerful Republicans who can try to stop the Democrats from doing things that they believe will be bad for the country. Also, the Democrats do not always agree with each other on what to do. And if enough people decide to vote against Democrats in the next election, then they will lose power. In a republic like the United States, no party can do whatever they want. All politicians have to argue, compromise, and make deals with each other to get things done. They have to answer to the people and take responsibility for their mistakes.

The USA's large cultural, economic, and military influence has made the foreign policy of the United States, or relations with other countries, an especially important topic in American politics, and the politics of many other countries.

The climate varies along with the geography, from tropical (hot and wet in summer, warm and dry in winter) in Florida to tundra (cold all year) in Alaska. Large parts of the country have warm summers and cold winters. Some parts of the United States, like parts of California, have a Mediterranean climate.

11% of the people in the United States are foreign born. 18% speak a language other than English at home. For people 25 and older, 80% are high schoolgraduates while 25% have a bachelor's degree or higher.

The 2000 Census counted self-reported ancestry. It identified 43 million German-Americans, 30.5 million Irish-Americans, 24.9 million African-Americans, 24.5 million English-Americans, and 18.4 million Mexican-Americans.

The socialstructure of the United States has a big range. This means that some Americans are much, much richer than others. The average (median) income for an American was $37,000 a year in 2002. However, the richest 1% of Americans have as much money as the poorest 90%. 51% of all households have access to a computer and 41% had access to the Internet in 2000, a figure which had grown to 75% in 2004. Also, 67.9% of American families owned their homes in 2002. There are 200 million cars in the United States, two for every three Americans. The debt has grown to over $16,000,000,000,000.[12]

The United States is one of the most religious countries in the Western World, and most Americans believe in God. The number of Christians in the U.S. has gone down. 86.2% called themselves Christian in 1990 and 78.4% said this in 2007. The others include Judaism (1.7%), Islam (0.8%), Buddhism (0.7%), Hinduism (0.4%), and Unitarian Universalism (0.3%). Those who have no religion are at 16.1%. There is a large difference between those who say that they belong to a religion and those who are members of a religious body of that religion.[14]

American popular culture goes out to many places in the world. It has a large influence on most of the world, especially the Western world. American music is heard all over the world, and American movies and television shows can be seen in most countries.

The American flag is made up of 50 stars on a blue background, and has 13 stripes, seven red and six white. It is one of many symbols of the United States like the Bald Eagle. The 50 stars represent the 50 states. The red stands for courage. The blue stands for justice. The white represents peace and cleanness. The 13 stripes represent the 13 original colonies.[18]